<!DOCTYPE html>
<html>
    <body>
        <style>
            #foo {
                counter-set: foo calc(sign(1em - 1px));
                counter-increment: bar calc(sign(1em - 1px));
                counter-reset: baz calc(sign(1em - 1px));
            }
        </style>
        <div>
            <div id="foo"></div>
        </div>
    </body>
</html>
